Nitrogen filling tyres

[Tony B]

A place near me is now offering this service at £1 per tyre. I know it makes sense on large hot running wheels. Apparently teh tubed type of tyre on the Dodge can be done very easily. Anyone any ideas or information on the pros and cons. Most important, can you mix N & compresed air in emergency?

[antarmike]

I had tyres filled with Nitrous Oxide, Advantage/ they didn't feel any pain if they got punctured.....

[sirhc]

Tony,

 

The composition of air is as follows:

 

Nitrogen N2 78.084%

Oxygen O2 20.947%

Argon Ar 0.934%

Carbon Dioxide CO2 0.033%

Neon Ne 18.2 parts per million

Helium He 5.2 parts per million

Krypton Kr 1.1 parts per million

Sulfur dioxide SO2 1.0 parts per million

Methane CH4 2.0 parts per million

Hydrogen H2 0.5 parts per million

Nitrous Oxide N2O 0.5 parts per million

Xenon Xe 0.09 parts per million

Ozone O3 0.07 parts per million

Nitrogen dioxide NO2 0.02 parts per million

Iodine I2 0.01 parts per million

Carbon monoxide CO trace

Ammonia NH3 trace

 

Therefore when you inflate a tyre with air, you are inflating it with 78% Nitrogen. Why would there be a problem with mixing Nitrogen and compressed air?! :nut:

 

Chris

[antarmike]

Seeing as compressed air is mostly Nitrogen, I can't see any compatibility problems, (cynically since compressed air is mostly Nitrogen can't see any possible advantage in using Nitrogen......)

[Tony B]

Just looked up the density's. Of course temprature is the factor. I've heard N is supposed to run cooler, so saves wear. The thought of NO2 in the tyres is hilarious (Sorry pills in post, again!) :-D Apparently on really heavy machinery the brakeing force can cause so much heat in tyres they catch fire, hence the use of N.

[griff66]

CON 1 quid plus vat !i take it your mv aint going to 40,000 feet, n2 larger molecules less likely to penetrate inner tube/tire wall less corrosive blah blah the tires will be fecked before u get any miniscule benefit

[Marmite!!]

From the AA

 

Filling Tyres with Nitrogen

 

Beneficial in specialist applications

The air we breath (and the normal compressed air used to inflate tyres) contains 78% Nitrogen, 21% Oxygen and 1% other gases.

Purified nitrogen has been used to inflate tyres on aircraft and racing cars for many years, but now some tyre specialists are offering nitrogen inflation for ordinary car and van tyres.

 

The advantages of using nitrogen in specialist applications are clear

 

• Planes fly at heights where temperatures may be as low as -40C. Any moisture in the tyres can freeze causing vibration and balance problems when landing. Pure nitrogen is dry so eliminates this problem (as would using dried compressed air)
  
• In motor sport the smallest fraction of a second can make the difference between winning and losing. Filling with nitrogen can reduce tyre pressure variation caused by changes in tyre temperature.
  

For passenger car applications the main claims seem to be

 

• Reduced corrosion – because unlike air there's no moisture in pure nitrogen
  
• Slower rate of pressure loss – because nitrogen molecules are larger than oxygen molecules (which make up 21% of compressed air)
  

Leakage can occur through the tyre's inner liner but can also occur through the valve, punctures, or failure of the seal between tyre and wheel rim. Pure nitrogen might leak more slowly through the liner, but regular checks of tyre condition and pressures will still be essential.

Corrosion of the tyre through use of normal compressed air alone is most unlikely because only the outer tread band of a car tyre contains steel – the amount of moisture reaching it from the inside is minimal.

Changing to nitrogen involves removing all the air which is already in the tyres and then re-inflating them with purified compressed nitrogen. There will be a one-off charge per tyre but once filled with nitrogen any future top-ups would also have to be with nitrogen if any advantages are to be maintained.

Overall, while accepting the possibility of purified nitrogen being of benefit in certain applications, we don't think that the cost and possible inconvenience are justified for normal passenger car use.

[Tony B]

So just another money maker for the boy racer market then? Wonder how long before all the tyre places offer it?

[griff66]

Big con

[sirhc]

So just another money maker for the boy racer market then? Wonder how long before all the tyre places offer it?

 

Yes, but I heard they work well with a broquet! :-D

[Tony B]

Now, my practical experience of the Brocquet is that they do work. I ran an old Montego, suposedly unusable with unleaded petrol for a good few years with a Brocquet. Still got the Broquet.

[Richard Farrant]

Now, my practical experience of the Brocquet is that they do work. I ran an old Montego, suposedly unusable with unleaded petrol for a good few years with a Brocquet. Still got the Broquet.

 

The old Montego would have gone just as long, if you had put the Brocquet in the glove box instead of the tank.

 

:-D

[Tony B]

Still, it was transfered to the next victim, an old Subaru L series. On that, though engine running fine, the MOT emissions, no cat of course, were so low the engine shouldn't have been running. :cool2: Mibd you, I did have an old Series 1 that had belonged to a White Witch. In the dashboard was a little sacking bag filled with various weird things. I was told it would be unlucky to take it out. So I did! Then had a puncture , the rad hose go and distributor cap crack in a week. Put it back in and no more problems.

Edited November 14, 2010 by Tony B

[radiomike7]

Many good answers including the smaller size of oxygen molecules but it assumes that you have 100% nitrogen which of course you don't as the tyre is full of air before you even start inflating it. The only way to ensure 100% nitrogen would be to fit and inflate the tyre in a nitrogen filled environment.

[N.O.S.]

Useful in preventing explosive blow-outs if you are running earthmovers under conditions which might lead to build-up of heat e.g. very large dumptrucks (>100t) or wheel loaders on steelworks hot slag duty etc (although slag duty machines are often tyre-filled).

[brianthesnail96]

The tyres on my Marina (actually ones liberated from a Triumph Spitfire, including rims) are apparently Nitrogen filled. As yet, they haven't gone flat... other than that, I can't say I've noticed any difference, it still understeers at any opportunity

[antarmike]

Surely if Air is 78% Nitrogen, and these molecules are too big to escape, then a tyre filled with air can only delate to 78%, ie all the nitrogen Molecules are retained. If you wait until all the tiny Oxygen molecules have escaped before you refill the tyre with air you are replacing the missing 22% with a mixture containing 22% oxygen and 78% Nitrogen. The oxygen in the tyre after one re-pressurisation now only contains 22% of 22% Oxygen, (instead of the original 22% of 100?)or 4.84% oxygen.

 

This means the tyre is already 95.16% Nitrogen. if you then wait until all this oxygen escapes, then refill with air you are putting in 22% of 4.84% or 1.065% of the total content of the tyre. Nitrogen will then be 98.4% of the total.

 

Let this tiny bit of Oxygen squeeze out through the tube and refill with air and you will have nigh on Pure Nitrogen in your tyre (Well 99.75%) , and it only cost you a bit of waiting....Or so it seems to me....

 

Could it be that most people have nigh on pure Nitrogen in their tyres without even realising it??

Edited November 14, 2010 by antarmike

[Essex5]

......let this tiny bit of Oxygen squeeze out through the tube and refill with air and you will have nigh on Pure Nitrogen in your tyre (Well 99.75%) , and it only cost you a bit of waiting....Or so it seems to me....

 

Sounds too good to be true - on the other hand, I can't fault your logic :thumbsup:

 

Ever since I first heard of it, I had a feeling that this Nitrogen filling scheme was a con - now I'm sure of it!!

 

John

[Axenige]

I think for MV's there no real need unless your restoring a B 17 flying fortress and intend to fly it at high altitude or next weekend you intend to take your custom supercharge M3 White Scot car down the quarter strip at Santa Pod :-D as nitrogen filled tyres only really make a difference at the extreme of tyre operating limits.

 

Nige H

[radiomike7]

 

Could it be that most people have nigh on pure Nitrogen in their tyres without even realising it??

 

Good point, except that you would not want to wait until the tyre was at 78% pressure before re-filling so it would take a bit longer at say 90%.

[johnwardle]

Back in the 1970s I worked as a mobile tyre fitter repairing punctures on farms I always carried a cylinder of nitrogen as a standby in case the compressor wouldn't start. So there is nothing new in using nitrogen to inflate tyres! This is just another way to make money, like charging for a new tubeless valve, even though the tyres are tubed. p.s. none of the farmers reported cooler tyres or better economy.

[Stone]

The advantages of using nitrogen in specialist applications are clear

 

• Planes fly at heights where temperatures may be as low as -40C. Any moisture in the tyres can freeze causing vibration and balance problems when landing. Pure nitrogen is dry so eliminates this problem (as would using dried compressed air)

 

Passenger car applications the main claims seem to be

 

• Reduced corrosion – because unlike air there's no moisture in pure nitrogen

Just to add to Lee's post - these two points about moisture are only valid when filling with DRY nitrogen. As it cost approx 3x as much as regular nitrogen when I was last involved with it the fitters are quite unlikely to be wasting it on your tyres! (we used it for backfilling underwater vehicles after servicing - and then the corrosion-reducing qualities are very desirable as it also keeps the seawater out!)

 

I can't see how any regular source of compressed air with a working dessicator would be in any way inferior to nitrogen-filling. The only possible advantage would be if it helped stop pyrolysis (see here) and thus tyre explosions - but I was under the impression that they were catalysed by the rubber's breakdown products...

 

On regular road-going tyres: a con.

 

Stone